From 9cc12ad6db55d7d902260fead28a91710dd5dbe5 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 6 Oct 2017 09:13:46 +0200 Subject: [PATCH] infiniband: add MMU dependency for user_mem The infiniband subsystem causes a link failure when the umem driver is built on MMU-less systems: mm/mmu_notifier.o: In function `do_mmu_notifier_register': mmu_notifier.c:(.text+0x32): undefined reference to `mm_take_all_locks' drivers/infiniband/core/umem.o: In function `ib_umem_get': umem.c:(.text+0x132): undefined reference to `can_do_mlock' drivers/infiniband/core/umem_odp.o: In function `ib_umem_odp_map_dma_pages': umem_odp.c:(.text+0x766): undefined reference to `get_user_pages_remote' This bug has existed for a while but only become apparent in ARM randconfig builds when the dependency on PCI was lifted, as none of the ARM-NOMMU targets support PCI at the moment. We could probably get the umem driver to build by providing an alternative implementation 'can_do_mlock()' that returns false on NOMMU-systems, but then we'd still have a problem with the mmu-notifiers required by CONFIG_INFINIBAND_ON_DEMAND_PAGING, so simply forbidding umem with NOMMU seems like the simplest workaround. Fixes: 931bc0d91639 ("IB: Move PCI dependency from root KConfig to HW's KConfigs") Signed-off-by: Arnd Bergmann Signed-off-by: Doug Ledford --- drivers/infiniband/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/infiniband/Kconfig b/drivers/infiniband/Kconfig index b62b3b1e09cd..98ac46ed7214 100644 --- a/drivers/infiniband/Kconfig +++ b/drivers/infiniband/Kconfig @@ -45,6 +45,7 @@ config INFINIBAND_EXP_USER_ACCESS config INFINIBAND_USER_MEM bool depends on INFINIBAND_USER_ACCESS != n + depends on MMU default y config INFINIBAND_ON_DEMAND_PAGING